Carlson Shane R, Netz Roland R
Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany.
Nano Lett. 2025 Oct 29;25(43):15605-15612. doi: 10.1021/acs.nanolett.5c03950. Epub 2025 Oct 3.
For an accurate description of nanofluidic systems, it is crucial to account for the transport properties of liquids at surfaces on subnanometer scales, where the finite range of surface-liquid interactions implies both spatially extended surface-liquid friction and modified interfacial viscosity. This is accounted for via generalized, position-dependent friction-coefficient and interfacial viscosity profiles, which enable the accurate description of interfacial flow at the nanoscale using the Stokes equation. Such profiles are extracted from nonequilibrium molecular dynamics simulations of water on polar, nonpolar, fluorinated, and unfluorinated alkane and alcohol self-assembled monolayers spanning a wide range of wetting characteristics. The Navier friction coefficient, interfacial viscosity excess, and depletion length are found to be interrelated through power laws and to scale exponentially with the work of adhesion. Our framework establishes a foundation for describing subnanometer interfacial fluid flow with implications for electrokinetics, biophysics, and nanofluidics.
对于纳米流体系统的准确描述，考虑液体在亚纳米尺度表面的输运性质至关重要，在该尺度下，表面 - 液体相互作用的有限范围意味着空间扩展的表面 - 液体摩擦以及修正的界面粘度。这通过广义的、位置相关的摩擦系数和界面粘度分布来解释，其能够使用斯托克斯方程对纳米尺度的界面流动进行准确描述。此类分布是从跨越广泛润湿性特征的极性、非极性、氟化和未氟化的烷烃及醇类自组装单分子层上的水的非平衡分子动力学模拟中提取的。发现纳维摩擦系数、界面粘度过剩和耗尽长度通过幂律相互关联，并随粘附功呈指数缩放。我们的框架为描述亚纳米界面流体流动奠定了基础，对电动学、生物物理学和纳米流体学具有重要意义。
